Various configurations and models of liquid dispensers, particularly liquid soap dispensers, are well known in the art. Conventional dispensers utilized, for example, in public restrooms and the like, are wall mounted units that typically include a housing structure that is permanently affixed to a wall. These dispensers may include an access door or member so that the dispenser can be opened by a maintenance person for refilling or servicing. With certain types of dispensers, separate refill cartridges are inserted into the housing structure. With other types of dispensers, the maintenance technician must directly refill a reservoir provided in the housing structure. The dispensers typically include a delivery device, such as a dosing pump, and a device such as a lever or button for actuating the dosing pump. The dispensers may be vented or unvented.
The conventional dispensers depend on the continued maintenance and operability of the housing structure, and particularly the dosing pump, that is permanently affixed to the wall. If the housing structure or dosing pump is damaged or vandalized, the dispenser becomes inoperable and must be replaced. The conventional dispensers also depend on a supply system wherein additional liquid soap must be separately stored, transported, and loaded into the dispensers. This process entails unnecessary logistic and manpower resources.
Advancements in viscous liquid dispensers are described, for example, in U.S. Pat. Nos. 6,533,145; 6,543,651; 6,575,334; and 6,575,335. These references describe various configurations of viscous liquid dispensers having a housing that defines an integral sealed internal liquid reservoir. In other words, the liquid reservoir is not a separate component from the housing, such as a cartridge or the like. The housing may be comprised of wall members that give the dispenser its outward appearance and also define the internal liquid reservoir. A manually actuated pump mechanism is disposed at least partially within the reservoir and has a delivery end that extends out of the reservoir and is actuated by a user to dispense the viscous liquid. The back side of the housing attaches to a bracket mounted on a wall or other supporting structure such that the bracket is not visible. When depleted, the dispenser is simply removed from the bracket and replaced with another dispenser.
Automation is also a desirable feature in the industry for many dispenser environments, such as public restrooms and the like. In this regard, various electronic dispenser designs have been suggested for dispensing a measured amount of stored liquid either automatically upon sensing the presence of a user, or upon manual actuation of an automated dispensing mechanism.
The present invention offers an automated electronic dispenser that combines the advantages of automatic “hands-free” dispensing with the improved dispensers such as those described in the U.S. patents referenced above.